Starting with Kodi v15 (Isengard) there's a dedicated addon available for owners of VBox TV Gateway devices. This post contains some general notes about it as well as information about how to file bug reports, contribute code and so on.

New features compared to using pvr.iptvsimple:

supports scheduling/management/playback of recordings

supports timeshifting (needs to be enabled in the addon settings)

supports showing signal status

supports using an external XMLTV file in case the OTA EPG is not enough

Requirements:

You'll need firmware version 2.47 in order to use the addon. The addon will complain and show an error notification if your firmware is too old.

The source code is available at https://github.com/kodi-pvr/pvr.vbox for anyone who is interested. The README contains some general information regarding the addon's settings, plus some technical notes for developers. If you want to contribute code, please fork the repository and create pull requests for your changes.